At present, touch screen technology has been increasingly applied in display technique. The existing touch screen technology mainly comprises resistive touch screen, capacitive touch screen and infrared optical touch screen. Since the capacitive touch screen has higher speed response than resistive touch screen, and can realize multi-point touch, it has a good market prospect in the field of touch screen; infrared optical touch screen technology is mainly applied in the large size touch screen.
For capacitive touch screen, currently it can usually be realized with the following three types of technologies: the OGS technology, which directly attaches a touch screen to a display panel; the in cell technology, which embeds a touch panel into a panel; and the on cell technology, which embeds a touch screen between a display panel and a polarizer. Since the attaching technology requires additional purchasing the touch screen, the cost being high and the thickness of the panel being increased, it has gradually be eliminated. For the in cell technology, as the touch circuit is within the display panel, the noise of the touch circuit has a great disturbance to the electric field inside the display panel, this technology is still not mature. Therefore, the on cell technology using multilayer or single layer ITO has attracted more and more attention.
However, the multilayer technology has multiple processes of exposure and development, the cost is high, and it is difficult for the promotion of the technology. Single layer ITO technology has many shortcomings due to the damages to the display of high annealing temperature, the large resistance of ITO, being apt to be scratched during the production process, and other reasons.